Keyboard control



A TTRNEYS INVENTOK H. J. NICHOLS KEYBOARD CONTROL Filed Feb. 11, 1955 Nov. 8, 1938.

Patented Nov. 8, 1938 y UNITED STATES KEYBOARD CONTROL Harry J. Nichols, Dayton, Ohio, assignor to International Business Machines Corporation, New York, N. Y., a corporation of New York Application February 11,1935, serial No. 5,958

This invention relates toA a keyboard control and more particularly to a keyboard interlocking means.

It is the principal object of the invention to provide in conjunction with a keyboard a simple and effective means for preventing improper operation of the mechanism associated with the keyboard when two or more keys are operated simultaneously, which means does not undesirably decrease the lightness of touch or the speed of response of the keyboard.

It is a further object to provide such a means which can readily be arranged to interlock predetermined keys or groups of keys either adjacent or spaced from each other.

It is a further object to provide a simple and effective interlock means, particularly applicable to a printing telegraph system, for preventing simultaneous operation of more than one key at 25 of the keyboard.

Other objects and advantages will be apparent from the following description, the accompanying drawing, and the appended claim.

30 Fig. 1 is an enlarged detailed view oi' a preferred form of pendant interlock member forming part of the invention;

Fig. 2 is a front view of a keyboard guide strip or comb with a series of key levers in position therein, illustrating one application of the interlock member, of Fig. 1;

Fig.3 is a side view. of the assembly shown in Fig. 2 taken in part section as indicated;

Fig. 4 is a top view of the assembly shown in Fig..2 taken in part section as indicated;

Fig. 5 is a view similar to Fig. 2 showing another embodiment of the invention;

Fig. 6 is a top view in part section of Fig. 5;

Fig. 7 is yet another view similar to Fig. 2,

45 showing another embodiment of the invention;

Fig. 8 is a top view in part section of Fig. '7;

Fig. 9 is a detailed view in part section show-- ing a preferred manner of mounting the pendant member of the interlock; and

50 Fig. 10 is a side view of a modiiied arrangement.

Referring to the drawing which shows a preferred embodiment of the invention, although various forms of keyboard may be used, that 55 shown is of the general form of a typewriter keyboard. It is provided with a set of keys arranged in the well known typewriter manner, the key levers associated with the keys being pivotally mounted on a c'ommon shaft and being spring held in normal up position. Referring now to l' Fig'. 2, it is noted that the outer ends of the key levers 2li are properly spaced and restricted laterally and in their oscillatory movement by guide member or "comb 2| having a series of Aequally spaced guide slots 2|S punched therein. 10 Each key lever is inserted through and works within one of these guide slots. As will be more fully explained hereinafter, all guide slots may not be provided with a key lever. Key lever is shown in the depressed or down position, 15 the other key levers being shown in normal position. The interlocking members, exempliiied by pendants lll, are preferably mounted on the guide comb 2|, but may of course be mounted on a separate member provided for the purpose. 20

Referring now to Fig. 1, avpreferred form of pendant interlock member I0 (briefly called pendant I0) is shown, but I wish to state that the invention is not limited to this particular form, as other forms may be used without departing from the invention. 'I'he form shown is mainly preferred for its simplicity in form, ease in manufacture, and because there are .no projecting points liable to bend or to gouge the mounting strip.

Pendant I0 is preferably a flat plate in the form of two intersecting discs of unequal size, the smaller disc having a hole |011. concentric therewith. The diameter of the larger disc should preferably be equal to the center spacing of the guide slots 2|S, so that when mounted in sexies, each pendant will be equally deflected upon the depression o! a key lever. Each pendant is pivotally mounted on guide comb 2| by suitable means such as a shoulder rivet 23 (see 40 Fig. 9) located on the median line between adjacent guide slots and at such a level that when swung sidewise by a key lever, the edge of the pendant will be effective to prevent the depression of the adjacent key lever, yet avoid any binding action. Good results are obtained by mounting the centers of the pivots substantially in the plane of the lower edges of the key levers.

When two pendants are to be mounted on opposite sides of the guide comb, a special problem is presented in obtaining a satisfactory pivot for the pendants which will be ilrm and strong, but which will not bind. Fig. 9, besides showing a shoulder rivet 23 of ordinary design, shows also a double pivot consisting of a solid rivet 24 56 and a hollow rivet 25 of the same outside diameter as rivet 24 secured on the shank of rivet 24 as clearly shown. rI'hus both pendants I0 and I0 are securely positioned in place in such manner that they swing freely and with no tendency to bind. This construction gives very satisfactory results.

Referring now to Figs. 2, 3 and 4 which show an interlock arrangement designed to interlock adjacent key levers only, pendants Il) and I0 are mounted alternately on opposite sides of guide comb 2I, the pendants of the near side being indicated by I0, and those on the far side by I 0. The operation is as followsz-Normally all pendants hang free in vertical position by reason of the center of gravity of the pendant being below the pivot point. When a key lever, as for example 20', is depressed, the pendants on each side thereof are swung aside by the key lever, blocking the adjacent guide slots and preventing depression of the adjacent keys so long as key 20' remains depressed. When key 2li' is released, its associated return spring (not shown) restores same to normal position, thereby permitting the displaced pendants to return to normal position. It is to be noted that in this embodiment, the interlocking action is restricted to the adjacent key levers in all cases, this resulting from the fact that the pendants are al- .ternately placed on opposite sides of the key lever guide. This construction is particularly adapted to applications where the interlock is intended to prevent operator errors due to striking two keys simultaneously with one finger, and assures that only one key of the pair struck can register.

Figs. 5 and 6 illustrate anembodiment in which more extensive interlocking is provided. In this case, as an example, it is assumed that the interlock arrangement is to interlock two or three key levers on either side of the one depressed. To facilitate the analysis, the key levers are numbered serially 1 to 8 inclusive, while the pendants are lettered a, a', b, b' etc., the prime letters designating pendants on the far side of the guide comb. As shown, pendants in groups of three are positioned adjacent each other on the same side of comb 20, alternating and overlapping with other independent groups of pendants on the opposite side of the lcomb. The relation of all pendants of a group is such that when a key lever is depressed, the pendant or pendants associated therewith are moved, and a similar motion 1s imparted to such other pendants of the group as lie to the same side of the depressed key lever. .Let it be assumed that key 4 is depressed as shown 1n Fig. 5, then pendants a, b, c, c are swung left, while pendants d', e' are swung right. Hence key levers I, 2, 3 and 5, 6 are locked up by key lever 4. If key 3 is depressed, key levers I, 2 and 4, 5, 6 are locked up. If key 5 is depressed, key levers 3, 4 and 6, 1, 8 are locked up, and so on. While an arrangement has been shown in Figs. 5 and 6 in which the pendants are arranged in groups of three, it is clear that the groups could be enlarged to any desired number; for instance, the entire number of pendants can be divided into only two groups so that keys of either half the entire keyboard can be interlocked independently of the other half.

Referring now to Figs. 7 and 8, an example of interlocking according to the invention is shown in which key levers next in order on the keyboard are interlocked, even though they are separated by unused key positions. The system oi' designation is as before. One unused key position intervenes between keys 3 and 4, and two unused key positions between keys 5 and 6. If key 3 is depressed, key levers 2 and 4 are locked up; and likewise, when key 5 is depressed, key levers 4 and 6 are locked up and so on.

In some cases it is desired to provide interlocking action between selected keys whose key levers may be separated from each other by other key levers which it is not desired to interlock. For instance, in the usual typewriter keyboard the key levers of adjacent keys in any horizontal row are usually separated from each other by intervening key levers. The present invention provides an arrangement by which an interlocking action may be obtained between such adjacent keys in a very simple manner. Referring to Fig. l0, key lever 20 is shortened so as to work in, but not beyond slot 2IS. Pendants I0 and I0 are mounted on each side of guide member 2 I, but only pendant I0' is affected by the operation of key lever 20. Assuming that one or more short key levers such as that shown in Fig. 10 are interposed between the regular key levers, shown in Figs. 3 to 8, the back or prime pendants will be operated normally, while the front pendants will transfer interlocking action across the short key lever positions without interference therewith. The action of the front pendants will thus be similar to the pendants working across the unoccupied slots in Figs. '7 and 8. In this manner, interlocking action can be transferred across keys to the other keys beyond. Similar variations in interlocking action may be obtained by notching the front or back portions oi selected key levers to permit the associated front or back pendants to work unimpeded therethrough, or by mounting pendants at diiferent levels.

Without further analysis, it will be evident that by following the methods and constructions illustrated in the examples, interlocking arrangements of many kinds to suit various operating conditions may be derived. Thus the entire keyboard can be interlocked by mounting all pendants on the same side of the guide member; or the keys of one half the keyboard can be interlocked independently of the other half by dividing the pendants into two series mounted on opposite sides of the guide member, or various other combinations may be produced.

While the forms of apparatus herein described constitute preferred embodiments of the invention, it is to be understood that the invention is not limited to these precise forms of apparatus, and that changes may be made therein without departing from the scopeof the invention which is dened in the appended claim.

Whatis claimed is: In keyboard interlocking mechanism in combination with a plurality of key levers and a slotted guide member therefor, a pair of interlocking members, means for pivotally mounting said members on said guide member comprising a stud extending through said guide and having a portion on one side of said guide for mounting one of said members, and having a portion oi' reduced diameter extending to the other side oi' said guide, and a sleeve rotatably mounted on said reduced portion, said sleeve providing a mounting for the other of said interlocking members.

HARRY J. NICHOLS. 

